Contbol mechanism fob stokers



Filed April 19. 1920 2 Sheets-Sheet 1 if., c. 4:1; fwn \...,.1 1.55m 13d... El,

Y Jk Jan. 15, 1924.

J. BRESLOVE CONTROL MECHANISM FOR STOKERS Filed April 19. 19o 2 sheets-sheet 2-- Patented J an. 15, 1924.

UNITED STATES JOSEPH BRESLOVE, OF PITTSBURGH, PENNSYLVANIA.

CONTROL MECHANISM FOR STOKERS.

Application tiled April 19, 1920. Serial No. 374,922.

l'ofall 'whom it may concern.'

Be it known that I, JOSEPH BnEsLovE, a citizenl'of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made a neivand useful Invention in Control Mechanism for Stokers, of which the following is n'specification.

This invention relates to control mechanisms and particularly to such mechanisms for use in connection with automatic stokers.

An object of the invention is to produce simple and effective means for controlling the delivery of fuel to an automatic stoker in response to variations in the steam output of the boiler associated therewith. \This may be indicated by variations in the pressure or liowof the steam.

to proportion the Adelivery o "-"stoker in" response to variations 1n the A further bject is to produce a new and improved control mechanism for automatic stokers which is adapted to control the operation of the 4fuel feeding ap aratus so as fuel to the amount of blast delivered to the Stoker.

A further object is to produce a control mechanism' for' automatic stokers in which. Ithe control ofthe fuel feeding apparatus is accomplished automatically through the agency' vof 'electrical devices and in whichv manually 'adjustable means are employed for accelerating or 'retarding the automatic operation of the'. 'fuel feeding appara-tus at lthe 'willof theoperator.-`

Afurther cbectfis to produce an automatic mechanism'for controlling the operation of the fuel 'feeding apparatus of an automatic Stoker in response to variations in the supply of draft or blast to the Stoker, in which means are emplo ed for automatically' stopping the fuel geding operation when the amount ow blast delivered falls below aI redetermined amountJ and for automatically' starting-'the delivery of fuel to the Stoker when the blast is increased a predetermined amount.

These and other objects which will be made more apparent throughout the further description of the invention are attained by means of apparatus embodying the features herein described and illustrated in the drawings accompanying and forming a part hereof.'

In the drawings,` 'Figure L is a diagramthe automatic control of thev'vstoke'rs.

matic view of a Stoker equipped with apparatus embodying my invention. Figure 2 is a wiring diagram which may be employed in connection with the apparatus ilaccomplished by employing a pressure rel sponsive device which responds to variations in steam pressure and in turn controls the operation of the blast delivery mechanism, or the fuel feeding mechanism, or both. The automatic control is sometimes accomplished in response to variations in the iiow of steam from the boiler or boilers in which case allow responsive device is substituted;

for the pressure responsive device as the v controlling agent of the blast deliveryand fuel feeding mechanism. Flow responsive devices have also been employed in connec.-

tion with pressure responsive devicesl and the arrangement has been such that the flow responsive device exerts modifyin -or controlling effect on the Voperation o thev prssureres'ponsive device. In 'fact2 changes in various operating conditions Ivvlthin the furnace and the boi er have been taken advantage, of for the purpose of accomplishing In addition, automatic control, inthe broad sense, has been applied to a battery of boilers and their co-operatin stokers so that the stokers are conti-olle as al'unit. On the other hand individual automatic control of the different stokers associated with such a battery of boilers has been employed. It will be apparent from the foregolng and from the further description that apparatus embodying my invention may be employed with control mechanism of the various types above mentioned and with apparatus arranged to accomplish either individual or unit control of stokers associated with a battery of boilers.

In the accompanying drawings m invention'` is illustrated in connection' wit a diagrammatic view 'of' avvellknown stoker in which each fuel feeding ram or plunger is actuated by a separate pressure actuated piston.

As shown, the furnace 4 is provided with a plurality ofhoppers' and each hopper' is associated with a separate fuel feeding ram (not shown) which .is actuated by means of a double acting piston located within a cylinder G. Each cylinder is provided with connecting piping 7 through which the steam entering'. and discharging from the cylinder passes. In the particular form of apparatus diagrammatically illustrated, each cylinder is provided with a control valve .which forms a part of an automatic unit diagrammatically illustrated at 8. The separate control valves forminor a part of the mechanism 8 are associatedj with a rotatable shaft 9 and are adapted to be actuated by that shaft. The particular type of valve employed for controlling the operation of the`fuel feeding rams 1s not important, so far as my invention is concerned, and consequently I have not illustrated the valve in detail. It ma be said, however, that the valve erriploye in connection with the typ of s toker diagrammatically illustrated ma be theColeautomatic valve fully illustratedAv and described in United States patent Vto Roe No. 951,340 of March 8, 1910.

In so farvas this invention is concerned, it is only necessary vto state that the separate control'valves of the separate cylinders are embodied in the valve mechanism S and that theoperation of each independent valve forming a part of this mechanism is con- 4trolled iby' the shaft 9 Consequently the timing o'f the` valveend the rate of operation'of the, fuel feeding ram associated with the valve is dependent' upon and varies with the speed of rotation of tlie shaft 9.

I n the drawings I have diagrammatically illustrated an'air duct 10 for delivering air to the furnace. vAsdiagrammatic'ally indicated, the ilt is .delivered to the duct 1() byafan or blower 11. The bloiv'er 11 may bedriven by any suitable apparatus, but as illustrated, is'` shown operatively connected to a steam turbine 12, which receives steam through a supply pipe 13 and an automatic valve 14. It will be, of course, understood that' the heat of the exhaust steam from the turbine may be conserved inI any of the various wfays vvell known in power plant practice. I have diagrammaticallv shown an automatic device 1 5 for controlling the operatign ofthe .valve lll and consequently the s eed of the turbine 12. As illustrated, this evice may be a pressure responsive device and it may be placed in communication with the steam boilers, associated with the furnace 4, through a pipe or passage 16. With this arrangemenuthe speed ofthe turbine and consequently the speedoftheblou-` er 11 `vill vary in mesponseto variations in the pressure delivered by the boilers, since the device l5 will open and close the valve 14 in response to variations in boiler pressure. It will, of course, be understood that so far as my invention is concerned, the device l5 may be of any type and it may respond in operation to any change in operatv ing conditions within the boiler or associated apparatus. ,is has been stated, it is desirable to vary the rate of fuel feed in responscto variations in the amount of blast delivered to the furnace or in other words it is desirable to vary the rate of fuel feed in response to variations in operating conditions so that the furnace or Stoker will respond to a change in operating conditions and will function insuch a way as. to return the furnace and its associated boiler back to normal operating conditions within a minimum period of time.'4 For this reason, I employ means for varying the operation of the fuel feeding rams in response to variations in the speed of the blast delivery apparatus. To state this more broadly` the apparatus illustrated is provided with means forvaryingthe rate of fuel feed in response to variations in the amount of blast'delivcred to the furnace.

The means illustrated for accomplishing this result includes an electric generator 17 operatively coupled to the shaft of the fan or blower 11 and so arranged that its speed will vary with variations in the s eed o'f thc fan orblower 11. As diagrammatically illustrated, the generator 17 i s operatively coupled to the shaft 18 of the turbine which is diagrammatically illustrated as being directly coupled tothe shaft of the fan o r blower 1l. The terminals of the generator are shown electrically connected to conductors 19 and 19.. Itwill, ofcourse, be 'a parent ,that variations in the speed of ,tie generator 17 will occasion variations in current voltage delivered by tliegeneratorand that this'varying voltage .may be employed in occasioning corresponding variations in the speed of rotation of the shaft 9, which forms a part ofthe automatic, valve mechanism 8. As illustrated, the shaft 9 is operatively coupled to an electric motor 20 which receives current from the generator 17. The speed of the motor with .relation to the speed of the generator may be proportioned by varying the windings of the motor in a manner well known fo electrical engineers, but with the arrangement described, var lations in the speed of the generator 17 will occasion corresponding variations in the speed of the motor 20 and consequently in the rate of thedelivery of fuel to the Stoker, since the operation of cach of the fuel feeding rains is dependent upon and is timed by the rotation of the Vshaft 9.

It will be apparent that the generator 17 may be either an alternating current or a connected to one brush ofrtlie-motor- 20.

The other brush of the generator .is elec` trically connected to a wire .22which is normally electrically connected 'to' the other brush of the generator. Under such conditions, the speed of the motor y2O will vary in direct ratio to variations :in the speed of=theA generator 17. A separatelyexcited ieldzfor both the generator and motor will'prefera bly be employed.: I 4have indicated a eld control rheostat .23 which may be employed in connection with the generatorfiel illustrated, the rheostat arm 2,4 .is 'provided with a handle 25 which may be -manuallyf operated for the purpose of varying the position of the arm withrelation to the terminals of the rhcostat and for .thereby varying the speed of the motor 20 independently of variations in the speed of the generator. I have also diagrammatically illustrated a field rheostat in the field 27 of theiv motor. This rheostat like fthe rheostat 23 may be adjusted manually to vary the speed of the motor independently of the speed of the generator.

With such apparatus, the motor may be adjusted to run at a predetermined speed when the generator or the blast delivery mechanism is running at normal speed. This adjustment may, of course, be accom plished with the rheostats 23 and 26. Variation in the speed of the blast delivery mechanism will occasion an automatic variation in the speed of the motor and consequently a variation in the rate of fuel delivery.

In the drawings I have shown an automatic switch 28 adapted to open the operating circuit of the motor 2O when the speed of the generator 17 falls below a redetermined speed. The device 28 prefera ly consists of a solenoid connected across the terminals of the generator and having its armature so arranged that a predetermined voltage will close the switch, whereas, a drop in voltage below a predetermined value will permit the plunger to be withdrawn by means of a spring 30 for the purpose of opening the switch (see Fig. l With such an arrangement, the solenoi will operate to open the switch and stop the motor when the volta e falls below a predetermined value and will close the switch after the voltage has increased above a determined value. Under such conditions, the fuel feed will be automatically cut oli when the blast or draft has been reduced to an amount which merely holds a banked lire, and will automatically start up as the blast or draft -is increased.

-Having thus described my invention, what I yclaim isy 1.. :In combination with a furnace and the boilerassociatcd therewith, a blast delivery mechanism, means responsive to changes in the .steam aoutput of the boiler` for driving said blast delivery mechanism, anrelectric generator operatively connected. to said Ameans,a fuel .feeding mechanism, means for controllingthe' operation thereof, and electrical apparatus responsive in operation'to variations. in the speed of said generator for Acontrolling--theoperation of said last mentioned means.x

2. Incombination with a furnace and the boiler'associated therewith, a fuel feeding-mechanism,"automatic means for.= controllingtthe "delivery: -of blast 'ita the I furnacefinrresponseto variations inthe steam output -o'f theiboiler, an :electric motor for controlling the operation of said fuel feeding mechanism, means responsive to variationsin the amountof blast delivered to the furnace for varying the speed of the motor, and automatic meansv forfeuttingy off the operating current to the motor when the blast deliveryf-falls-z below'- a Vpredetermined amountrand 'for'ldelivering' current to themotor when the blast delivery increases above a certain amount.

3. In combination with a Stoker and the boiler associated therewith, a. blast delivery mechanism, means responsive to variations in the steam output of the boiler for driving said blast delivery mechanism, an electric generator driven by said means, a fuel feeding mechanism, means for controlling the operation thereof, an electric motor receiving current from said generator for controlling the operation of said fuel-feed controlling means and manually controlled means for varying the speed of said motor independently of variations in the speed of said eneraton 4. n combina-tion with a furnace and the boiler associated therewith, a fuel feeding mechanism forming a part of the fur nace, a valve mechanism for controlling the operation of said fuel feeding mechanism, a fan for delivering blast to the furnace, apparatus for driving the fan, an electric generator operatively coupled to said a paratus, an elect-ric motor receiving current rom said generator and controlling the operation of said valve mechanism, and automatic means responsive to variations in the steam output of the boiler for controlling the s eed of said apparatus and thereby contro lin the delivery of blast and the rate of fue feed to the stoker.

5. In combination with a furnace and the boiler associated therewith, a blast delivery mechanism, means sfor driving said .mechanism at variablespeeds, anelectrie lgenerator driven by said means, a fuel-feeding mechanism, means .for controlling :the operation of said mechanism and a motor fordriving said controlling4 means Yreclaim-ng current from said generator' and adaptedto-increase and decrease in speed in response lito increases and decreases in .the ,speed of said generator.

6. In combination with a inl-'nace andathe associated boiler, a Ablast delivery mechanism, means responsive .to changes in the steam output ofthe boiler for-.driving- Said mechanism, a fuel feeding mec anism, means for controlling theoperation thereof, and interconnected electrical appanatus; :forcontrolling :the operation .of isaiol Last-.mentionecl means in response Ato xmliiations4 in the speed of `said blast delivery mechanism including a generator driyen by said dativing means and .a ,motor receiving .current therefromand dnivingesaid feed mechanism controlling means.

7. .In combination with .a furnace .and the associated boi1er,.a'blnwcr Eon delivering air underpressuretothe boiler, ;driv,. ing means therefor, means responsive to variations in thesteam outputo thehoiler.

for varyingthe speedof saitldri-vingmeans, an electric. generator. operatively coupled to saiddniving meansand adapted .to vary in speed ltherewith, a .fuel .feeding mechanism, timing means forcontrolling the operation thereg, amotorfreceiving current from said generator-and adapted to vary in speed in response to variations in current voltare occasionedbyvariations inthe speed of said generator, :for controlling the operation of saildi ,timing means.

.8. In .combination with a vfur-nace and the-,boiler associated therewith, a fuel feeding .mechanism for delivering f-uel to the furnace, ,a fan for delivering blast to the furnace, driving means for said fan, means respqnsiveito variations -n the steam output ofhheiboilerJor-controlling the speed of said driving means, :an .elect-ric .generator operatively" connected to said driving means and adapted to .vary in speed therewith, automatic.mpansfforcontrolling-the operation of said fuel ,feeding mechanism, an electric motori-ireceieingurrent from saidl generator andadaptedto vary in speed' inresponse to .variations in .current voltage occasioned by variations in .thefspeed of the generator for contnolling-the. operation of said automatic means.

In testimony whereof, I vhave hereunto Vsubscribed myname thisv '17" clay of April,

JOSEPH BRESLOVE. 

